1. Field of the Invention
This invention is concerned with trays and containers adaptable for holding food often containing fats, for cooking in a microwave oven.
2. Description of the Prior Art
It is well known in the art to produce various shaped articles from foamed and unfoamed polystyrene sheet by thermoforming methods. Many such articles are containers used for packaging foods.
Polystyrene containers, however, are melted by hot fats and can not be used to package fat-containing foods that are to be heated. Even when treated by radiation, the polystyrene containers still are not resistant to hot fats.
Surprisingly, it has been found that containers made from poly (p-methylstyrene), which are not per se resistant to hot fats, are resistant to hot fats when treated by radiation.